Save Earth from an asteroid on a collision course. You have a 15 minute countdown to destroy the asteroid!

Fly simulated rockets to intercept the asteroid and destroy it before it reaches the Earth. You will need to customize your rockets and carefully pilot them to hit the asteroid.

This game features simulated rocket physics. Some of these features include:

• RCS control and gimbaling
• Orbital mechanics and prediction
• Fuel weight and usage
• Atmospheric drag and heating (although heating is purely visual)

Controls:

Building mode:

• Click and drag pieces to place them
• You cannot remove pieces once they are placed, but you can move them around on the ship

Pilot mode:

• Shift increases throttle, control decreases
• A/D to steer rocket
• Toggle map mode with M or by zooming in/out. Both views are useful!
• Speed buttons control speed of physics (1x,2x,4x,8x)
• Camera buttons focus on earth, ship, or moon

Hints to win:

• To hit the asteroid, you need to be lined up precisely to the center of the asteroid icon in the map mode. The icons in the map view aren't very representative of their real size.  In the normal view mode, you will be able to easily see if you missed or hit the asteroid - an explosion happens if you hit it. The size of the explosion depends on how many explosives you have, and you need to destroy 90% of the asteroid
• It's best to reach orbit quickly to avoid losing speed to drag - so until the asteroid is very close, fly straight up first then adjust trajectory by burning in the right direction
• You can view your fuel reserves by looking at your fuel tanks in the normal view mode
• it really benefits the ship to be relatively balanced
• Nose pieces really reduce drag and allow extra thrusters to be placed above
• Thrusters must be connected to fuel tanks (and share fuel with other connected fuel tanks)
• You can see the asteroid's predicted location by hovering over your predicted path in the map view
• There's very little reason to turn RCS control off
• You will want to have high explosive payloads - try to get as many blue bomb pieces as possible. 3-4 of them will probably blow up almost the entire asteroid - you need to blow up 90%

Here's a full playthrough: